Free will has long been a fraught concept among philosophers and theologians. Now neuroscience is entering the fray.

For centuries, the idea that we are the authors of our own actions, beliefs, and desires has remained central to our sense of self. We choose whom to love, what thoughts to think, which impulses to resist. Or do we?

Neuroscience suggests something else. We are biochemical puppets, swayed by forces beyond our conscious control. So says Sam Harris, author of the new book, Free Will (Simon & Schuster), a broadside against the notion that we are in control of our own thoughts and actions. Harris's polemic arrives on the heels of Michael S. Gazzaniga's Who's In Charge? Free Will and the Science of the Brain (HarperCollins), and David Eagleman's Incognito: The Secret Lives of the Brain (Pantheon), both provocative forays into a debate that has in recent months spilled out onto op-ed and magazine pages, and countless blogs.

What's at stake? Just about everything: morality, law, religion, our understanding of accountability and personal accomplishment, even what it means to be human. Harris predicts that a declaration by the scientific community that free will is an illusion would set off "a culture war far more belligerent than the one that has been waged on the subject of evolution."

The Chronicle Review brought together some key thinkers to discuss what science can and cannot tell us about free will, and where our conclusions might take us.